Let me say with humility, I do not consider myself to be one of the bullet experts at this forum. After 40+ years of digging and dealing ACW bullets, I've learned a lot about them, but I don't think I'm a "top level" advisor on bullets. But since nobody else has answered your bullet-ID request, I'll give it a try.
To me it looks to be a slightly eroded .36 Colt, T&T#28. In addition to the general body shape, the measurements you report are extremely close to those reported in the Thomas-&-Thomas book for #28, the .36 Colt. By "slightly eroded" I mean some of its sharp corners and nose-tip have been somewhat rounded off by slight corrosion or "bumping" against other bullets in a cartridge box. I suspect erosion is a factor, because your bullet is 5 grains lighter and .02-inch shorter than T&T#28.
Regards,
Pete